It is a topic for a different thread maybe, or you can see the thousands upon thousands of threads discussing this very point on other discussion boards. I've even participated in a few of them.

It is e-ink, not an LCD screen. It works a lot like a book or a magazine or a newspaper. It only takes power to re-arrange the e-ink (e.g. turn the page) so the battery life is long (measured in days not hours), and in good lighting the print is as crisp as holding a piece of paper. It is not aimed at casual readers, tablet PC users, gamers, or the Kindle crowd. It is a tool for professionals who read and carry a lot of reports.

Believe it or not, it is the cutting edge of technology. Color screens are about 5 years off.